Is it me or my girlfriend causing problems?

[MM]

I don't understand why you proposed in the first place. You're not happy with the amount of affection she shows you, and instead of considering the possibility that maybe this is all she has to give you and either trying to appreciate other ways she shows she cares about you or just deciding it's not working and ending it, you get resentful and complain. And yes, she does sound somewhat demanding and irresponsible, but did you really think a ring was going to change that either? Stop doing things for her unless you genuinely want to do them, not because you're hoping to get something out of it or just want to shut her up, and if you're still not happy, let her go and move on.